I love Skuld!  The OVA cels of her are much nicer that that 
movie.  The movie cels have her looking older and more bratty.  
I like seeing her emotional side which shows up more in the 
OVA.  I'd collect more if AMG cels weren't so rare and not to 
mention expensive.

I still like original animation art.  Like you said with Tenshi ni 
Narumon some series are more collectible because of 
availability.  I hope that there continues to be a market for cels, 
but I fear that eventually only the high end cels will be traded 
and on a rarified person to person basis with anime merchants 
who are collectors themselves being the middlemen.  That 
means that we'll all have to make aquaintances with japanese 
dealers to keep our channels open.